Field of the Invention
The present invention relates to a display control device and an imaging device.
Description of Related Art
As an imaging device which captures an image such as a digital camera, an imaging device is known which performs various types of image processing on image data indicating captured images and displays a display image indicating display image data obtained through the image processing on a display device such as a display. For example, in an example shown in FIG. 7, an image-processing unit 940 generates moving image data, display image data 1, and display image data 2 which are re-sized depending on usage based on imago data from an imaging unit 920 (FIG. 9) and the image-processing unit 940 stores them in a memory. A moving image compression unit 950 stores compressed image data in the memory, the compressed image data being obtained by performing moving image compression processing on the display image data 1 read from the memory. Display control units 970-1 and 970-2 output the display image data 1 and 2 to display devices 20-1 and 20-2, respectively.
If a large amount of data is read from or written to a memory in parallel, it is difficult to ensure a bandwidth of a direct memory access bus (DMA bus, not shown) which connects the memory and each configuration element, and thus delay and congestion may occur. For example, there are cases in which a display image is displayed on the display device 20-1 while moving images of a 4K2K size (3840 pixels in a horizontal direction×2160 pixels in a vertical direction) are recorded. This is because the amount of DMA bus transfer data transferred via the DMA bus increases if the moving image data and the display image data 1 generated by the image-processing unit 940 are individually read from or written to each memory. In order to reduce the DMA bus transfer data, for example, the image-processing unit 940 does not generate the display image data 1 as shown in FIG. 8, and the display control unit 970-1 outputs the moving image data read from the memory to the display device 20-1.
On the other hand, in recent years, digital cameras having an edge-peaking function have been widely used. Edge peaking means image processing in which a predetermined edge emphasis color is superimposed on an image indicated by the image data in an edge area detected by causing a high-pass filter (HPF) to transmit data. By displaying an edge image obtained by the edge peaking on a display device, a user is notified of a position which is estimated to be in focus among captured images.
For example, the imaging device described in Japanese Unexamined Patent Application, First Publication No. 2009-231918 includes a peaking signal generation unit which generates a peaking signal from an input video signal, an operation unit which receives designation of a target area on which contour correction by a peaking signal is performed, and a control unit which generates an area gate signal describing position information corresponding to the designated area. The imaging device includes a mask-processing unit for outputting, based on an area gate signal, a video signal to which a peaking signal is added to the designated target area.
As shown in FIG. 8, display image data obtained by performing edge-peaking processing is also used as moving image data used for compression and recording. As shown in FIG. 9, an edge image is superimposed on not only a display image indicated by display image data to the display control units 970-1 and 970-2 but also an image indicated by moving image data output to the moving image compression unit 950. On the other hand, in order to output the display image data on which the edge image is superimposed from the display control units 970-1 and 970-2 as shown in FIG. 10, each of the display control units 970-1 and 970-2 requires an edge-peaking processing circuit which performs edge-peaking processing and a line memory which stores moving image data for adjusting a timing of superimposition with a generated edge image. Accordingly, a problem occurs that a hardware scale increases such that power consumption of the display control units 970-1 and 970-2 increases than the power consumption of a conventional digital camera.